This application seeks a five-year continuation of the Monitoring the Future (MTF) study, an ongoing epidemiological and etiological research and reporting project begun in 1975. In addition to being a basic research study, MTF has become the nation's most reliable source of information on trends in drug use among American adolescents, college students, and young adults. Nationally representative sample surveys will be conducted annually of 8th-, loth-, and i2th-grade students (about 16,000 in 140 schools per year per grade). A separate application seeks continuation of the mail follow-ups of high school graduates at modal ages 19-30,35,40, 45, and 50. The study's cohort-sequential longitudinal design permits the measurement and differentiation of three types of change-age (developmental), period (historical), and cohort. Each type has different classes of determinants, and all three types have been shown by this study to have occurred for most drugs. Factors that may explain historical trends and cohort differences will be monitored. MTF has the further objectives of documenting the natural history of drug use and related attitudes through middle adulthood, and determining the individual and contextual characteristics and social role transitions that contribute to change and stability in drug use and related attitudes. Many of these goals can be pursued using the existing cohort-sequential data;but the findings will be extended to new years, cohorts, and ages with the new data to be collected under this application and the separate follow-up application. The study will examine the importance of many other hypothesized psychological, behavioral, and social determinants of drug use (including attitudes and beliefs about drugs, counter-advertising, role-modeling, and access), as well as a range of potential consequences of drug use (including physical health, psychological well-being, status attainment, role performance, and drug abuse and dependence). The investigators will continue to facilitate the extensive use of MTF data by others for a wide range of research purposes. The study's very broad measurement covers (a) initiation, use, and cessation for a great many licit and illicit drugs;(b) attitudes and beliefs about these drugs, as well as perceived availability, peer norms, and norms among role model groups;(c) other behaviors and individual characteristics (delinquency, school performance, plans, aspirations, etc.);and (d) aspects of key social environments (home, work, school) and social role statuses, experiences, and transitions (marriage, pregnancy, parenthood, divorce). Study results will continue to have major implications for understanding and preventing drug use and abuse from adolescence through middle adulthood.